Gas-engine valve.



H. L.. JESSBN. GAS ENGINE VALVE. APPLIGATION FILED lungs, 190e.

Patented 0ot.5,1909.

INVENTOR,

W I TNESSES ATTORNEY.

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HENRY L. JESSEN, OF ALAMEDA, CALIFORNIA.

GAS-ENGINE VALVE.

Speceation of Letters Patent.

Patented Oct. 5, 1909.

Application filed March 26, 1908. Serial No. 423,333.

To all whom t may concern.'

Be it known that I, HENRY L. J ESSEN, a citizen of the United States,residing at Alameda, in the county of Alameda and State of California,have invented new and useful Improvements in Gas-Engine Valves, of whichthe following is a specication.

The object of the present invention is to provide an improved form ofexhaust valve for gas or gasolene engines, which will be more convenientin assembling, and will positively prevent any leakage through saidvalve, in the suction movement of the piston.

It is essential, in a gas engine, to maintain the proper proportionbetween the air and gas or vapor. If any part of the burned gases thathas been discharged through the exhaust valve is drawn back into thecylinder again, when a smaller volume is allowed to enter through thethrottle, then such proportion is changed, and the best results cannotbe obtained.

In a large gas engine of the type in which the speed is controlled by athrottle, or with a throttling governor, considerable trouble isexperienced from the fact that when the throttle is partly closed todraw in a small charge, the suction of the piston, in drawing in thecharge, is so powerful that it is difcult to prevent the exhaust valveopening due to this suction. To prevent this it has been heretoforenecessary to use a spring of great power in proportion to the workotherwise required to be done by said spring. But this is objectionable,on account of the fact that the great pressure exerted by this spring,operating several hundred times a minute, creates a great wear on theparts connected to the valve, so that these parts require to befrequently renewed.

The object of the present invention is to obviate the above difficultyand expense.

In the accompanying drawing, Figure 1 is a section through the exhaustvalve of a gas engine equipped with my improvement; Fig. 2 is a sideview on a smaller scale of a portion of a gas engine.

Referring to the drawing, 1 indicates the cylinder of the engineprovided with the usual cylinder head 2, and having the water coolingchamber 3. Said head is formed with a housing 4 to receive a valve cage5, having a seat 6 on the cylinder head. The housing and the valve cageare formed with apertures 7 leading to an exhaust conduit 8 formed inthe cylinder head. Said cage is formed with an elongated bearing 9 inwhich slides a valve stem 10, carrying at its inner end. the exhaustvalve 11 adapted to rest against a valve seat 12 upon the end of thecage. At its outer end the bearing is thread-y ed, as shown at 13, and anut 14 is screwed thereon, and bears upon a collar 15 surrounding thebearing, which collar is thereby pressed against a boss 16 formed uponthe cylinder head. By means of this nut, the cage is firmly drawnagainst the seat 6 formed in the cylinder head. This construction is ofgreat convenience in assembling the parts. It has heretofore been thepractice to form this cage so as to have two tight bearings or joints,one on the inside, and the other on the outside of the cylinder head. Ithas been diliicult to make these two joints tight at the same time. Theabove construction avoids this diiculty. Moreover, it enables the waterjacket 3 to be so formed as to extend into close proximity with thetubular bearing 9, which so far as my knowledge extends, has notheretofore been possible, and thus to maintain said bearing cool.

Upon the collar 15 are formed two forked lugs 18, in each of which ispivoted a locking lever 19, the outer ends of said levers connected by acoiled spring 20. Said levers are formed with Shoulders 21 which abutagainst the inner surface of a collar 22 screwed upon the threaded valvestem. lA coiled spring 23 is interposed between said collar 22 and thecollar 15, which spring normally presses said collar 22 outward and thusholds the valve against its seat. This construction, of the collar 21and the spring 23 for pressing against said collar to hold the valve toits seat, is, in general, the construction in common use. And, inconnection with this, it has been the practice to provide a lever 24,actuated by a cam 25 upon the engine, which lever, at the proper time,is operated by said cam 24 to depress the valve stem 10 and open theexhaust valve. This lever 24 I still employ, but it now bears against aconical wedge 26, which slidably engages the valve stem 10, and isnormally pressed away from the collar 22 by means of a light spring 27.This conical wedge is adapted to engage inclined surfaces 2S, formed onthe levers 19.

Vith this construction the following is the operation of the device.I/Vhen the lever 24 is actuated by the cam 25 to depress the valve stem,said lever no longer acts directly upon the stem, since the conicalwedge is not direct-ly connected to said stem, and the first effect ofsaid operation of the lever is to force said wedge against said slopingsurfaces 9S of the locking levers, and thereby move said locking leversapart. By this movement, the shoulders 21 on said levers are withdrawnfrom the inner surface of the collar Q2 so that said collar is now freeto move downward. The inner or under side of the conical wedge 2G thenbears against the outer end of the hub of the collar 20, and positivelypresses said collar inward against the act-ion of the coiled spring 28,thereby positively forcing inward the valve stem and opening the valve.As soon as the cam has rotated to suoli a point as to permit the lever24 to be withdrawn, to allow the valve 11 to return to its seat, thespring 93 returns the collar 22 to such a position that the shoulders 21on the locking levers 19 can again engage the same, which they do, owingto said levers 19 being drawn together by the coiled spring 20. rlhelight spring Q7 also returns the conical wedge to its original position.

l prefer to make the shoulders 21 of the levers 19 slightly beveled, forthe reason that the spring 20 then operates, by pulling together thelevers 19, to force the collar 22 outward, thereby drawing said exhaustvalve tight to its seat. Moreover by the beveled form of the wearingsurfaces, any wear upon the collar 22 or levers 19 is taken up.

I claim 1. In a gas engine, an exhaust valve, a

lcvcr for opening said valve at a suitable stage in the cycle of theengine, a spring for resisting said opening, means for positivelylocking said valve except at said stage, and means for withdrawing saidlocking means, actuated by said lever, substantially as described.

2. In a gas engine, an exhaust valve having a stem, means for openingsaid valve at a suitable stage in the cycle of the engine, a lockinglever for preventing said opening, said locking lever having an obliqueedge, and a device movable on the stem of the exhaust valve, andarranged to be actuated by said opening means by its engagement withsaid oblique edge to withdraw said locking lever, substantially asdescribed.

3. ln a gas engine, an exhaust valve having a stem, a disk, on saidstem, locking levers having shoulders adapted to engage said disk tolock said exhaust valve to its seat, said locking levers having obliqueedges, a spring connecting said locking levers, a lever for opening saidexhaust valve, and a cone movable on said valve stem and adapted to beactuated by said latter lever to engage said oblique shoulders towithdraw said locking levers, substantially as described.

In testimony whereof I have hereunto set my hand in the presence of twosubscribing witnesses.

HENRY L. J ESSEN.

lVitnesses F. M. VRIGHT, D. B. RICHARDS.

